<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>边框修饰</title>
  <style>
      .box{
          width: 100px;
          height: 100px;
          border: 1px solid;
          /*border-radius: 8px;*/
          /*border-top-left-radius: 20px;*/
          /*border-bottom-right-radius: 20px;*/

          border-radius: 10%;
          /*
             x-offset
             y-offset
             blur
             spread
             color
             inset  --- 内置阴影
          */
          box-shadow: 1px 1px 1px 1px #342020, 2px 2px 2px 2px red;

      }
  </style>
</head>
<body>


  <div class="box">

  </div>
</body>
</html>